At least five people have been killed and 18 injured after a gunman opened fire inside a gay club in the US state of Colorado on Saturday night.
Police said a suspect, named as Anderson Lee Aldrich, 22, is in custody and being treated for injuries.
Two “heroic” people in the club subdued the attacker, police said.
Club Q, in Colorado Springs, released a statement on Facebook saying it was “devastated by the senseless attack on our community”.
Police asked people to be patient while they work to identify victims and finalise the number of casualties.
Officers received an initial emergency call about an active shooter at 23:57 (06:57 GMT) on Saturday, they said.
The suspect was found inside the club. Two firearms were found at the scene, and the suspect is thought to have used a long rifle.
Police did not immediately suggest a motive for the shooting, and said the number of dead and injured could change as the investigation continues.
A fire department spokesman said casualties had been transported to hospitals very quickly, due to training for such events.
The FBI in nearby Denver said it was assisting local police with the incident.
Police chief Adrian Vasquez thanked the two club-goers who intervened to stop the shooter.
“Initial evidence and interviews indicate that the suspect entered Club Q and immediately began shooting at people inside as he moved further into the club,” he told a news conference on Sunday.
“While the suspect was inside of the club, at least two heroic people inside the club confronted and fought with the suspect and were able to stop the suspect from continuing to kill and harm others. We owe them a great debt of thanks.”
A statement on the Club Q Facebook page thanked “the quick reactions of heroic customers that subdued the gunman and ended this hate attack”.
The club was hosting a dance party at the time, and had planned to hold a performance event on Sunday evening to celebrate Transgender Day of Remembrance.
The club’s Facebook page has been inundated with comments and condolences from around the world.
One person wrote that the club had been “like a home” for her for many years, and she was “absolutely shattered” by the news.
“[I] met so many great people, I literally met my husband there, so it holds such a special place in my heart. Everyone was always so welcoming and kind through the years,” she wrote.
“I am so broken by this news,” another comment added.
“Club Q has been the heart of our community for so long and I am devastated and angered that this happened.”
The office of Colorado Springs mayor John Suthers called the event a tragedy.
In 2016, 49 people were killed and more than 50 injured in a shooting at the Pulse gay club in Orlando, Florida. At the time it was the deadliest mass shooting in US history.__BBC
